ATmega16U2 Atmel Corporation, ATmega16U2 Datasheet - Page 58

• Manufacturer Part Number: ATmega16U2
• Manufacturer: Atmel Corporation

Specifications of ATmega16U2

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 22
• Ext Interrupts: 21
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 5
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

Table 10-3.
7799D–AVR–11/10
WDP3
0
0
0
0
0
0
0
0
1
1
WDP2
Watchdog Timer Prescale Select, DIV = 0 (CLKwdt = CLK128 / 1)
0
0
0
0
1
1
1
1
0
0
WDP1
0
0
1
1
0
0
1
1
0
0
• Bit 3 - WDEWIF: Watchdog Early Warning Interrupt Flag
This bit is set when a first time-out occurs in the Watchdog Timer and if the WDEWIE bit is
enabled. WDEWIF is automatically cleared by hardware when executing the corresponding
interrupt handling vector. Alternatively, WDIF can be cleared by writing a logic one to the flag.
When the I-bit in SREG and WDEWIE are set, the Watchdog Time-out Interrupt is executed.
• Bit 2 - WDEWIE: Watchdog Early Warning Interrupt Enable
When this bit has been set by software, an interrupt will be generated on the watchdog interrupt
vector when the Early warning flag is set to one by hardware.
• Bit 1:0 - WCLKD[1:0]: Watchdog Timer Clock Divider
Table 10-2.
WCLKD2
WDP0
0
0
0
0
1
1
1
1
0
1
0
1
0
1
0
1
0
1
Watchdog Timer Clock Divider Configuration
Number of WDT Oscillator
Cycles before 1st time-out
1024K (1048576) cycles
128K (131072) cycles
256K (262144) cycles
512K (524288) cycles
16K (16384) cycles
32K (32768) cycles
64K (65536) cycles
2K (2048) cycles
4K (4096) cycles
8K (8192) cycles
(Early warning)
WCLKD1
0
0
1
1
0
0
1
1
WCLKD0
0
1
0
1
0
1
0
1
Early warning Typical
ATmega8U2/16U2/32U2
Time-out at
V
CC
0.125 s
16 ms
32 ms
64 ms
0.25 s
0.5 s
1.0 s
2.0 s
4.0 s
8.0 s
Mode
Clk
Clk
Clk
Clk
Clk
Clk
Clk
Clk
= 5.0V
WDT
WDT
WDT
WDT
WDT
WDT
WDT
WDT
= Clk
= Clk
= Clk
= Clk
= Clk
= Clk
= Clk
= Clk
128k
128k
128k
128k
128k
128k
128k
128k
Reset/Interrupt Typical
/ 3
/ 5
/ 7
/ 9
/ 11
/ 13
/ 15
Time-out at
V
Watchdog
CC
128 ms
0.250 s
32 ms
64 ms
16.0 s
0.5 s
1.0 s
2.0 s
4.0 s
8.0 s
= 5.0V
58